Electricity meter



(No Model.) 3 Sheets-Sheet 1.

A. RAPS.

ELECTRICITY METER.

No. 579,079; g Patented Mar. 16, 1897.

L1 I P lg 06 S e V 1" Q 2 g WIN/55555:

BY A 7'7'0/PWE Y:

(No Model.) 3 Sheets-811mb A. RAPS. 'ELEGTRIGITY METER.

Patented Mar i'J I G 1897' (No Model.) 3 sheets-sum 3. A. RAPS. ELECTRICITY METER.

Patented Mar. 16, 1897;

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AUGUST RAPS, OF BERLIN, GERMANY, ASSIGNOR TO SIEMENS do HALSKE, OF SAME PLACE.

.ELECTRICITY-METER.

SPECIFICATION forming part Of Letters Patent No. 579,07 9, dated March 1 6, 1897.. Application filed July 25, 1396. Serial No. 600,574. (No model.)

To all whom it may concern.-

Be it known that I, AUGUST RAPS, a snbject of the German Emperor, residing at Ber- 1i11,in the German Empire, have invented certain new and useful Improvements in Electricity-Meters; and I do here-by'declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it ap- IO pertains to make and use the same.

This invention relates to electricitymeters.

The invention consists in the instrument hereinafter described.

Of the accompanying drawings, Figure 1 is a side elevation of the complete instrument. Fig. 2 is a plan view seen from above. Fig. 3 is a vertical section in the line a [2, Fig. 2, less important parts being left out for the sake of clearness. Fig. 4 is a plan View showing only certain important parts of the instrument. Fig. 5 is a plan View of the com plete instrument seen from below, unimportant parts being left out for the sake of clearness. Fig. 6 is a diagram showing the elec trical connections of the different parts of the instrument.

The letters of reference indicate the same parts in all the figures.

In the drawings, m and m are the windings of an eleetromagnet E.

K is a cylindrical iron core placed between the poles of said electromagnet and preferably fixed in that position.

J is a coil of thin wire mounted on the spin 5 dle a and surrounding the iron core K in such a way that it can freely swing in the space left between said core and the polepieces of the electromagnet E.

s and s are two springs connecting the two 4: ends of the coil J electrically with a suitable source of electricity hereinafter to be more fully described and at the same time mechanically giving the coil J a certain position of rest from which it can only be deflected by 5 bending said springs s and 5 On the spindle a is mounted an index Z, carrying a very light and flexible arm f Bis a U-shaped rod pivoted on two pins 19 and p fastened in the frame of the instrument and forming geometrically an exact prolongation of the spindle a. On its one end,

projecting beyond the pin 19, the U-shaped rod B carries a counterweight G. 'On its other end it carries a light strip of metal f, which is dimensioned in such a way as to just swing free of the circumference of a disk R, likewise turning freely 011 the pin p and being coupled by a cog-wheel N with a suitable device D, such as is usually employed in similar instruments for registering the. number of revolutions performed by the disk R.

The metalstrip f fastened to the index Z, is made of such length as to intercept the strip f when the U-shaped rod B swings round the pivots p and p L and L are two ball-bearings carrying a spindle a in such a position that its geometrical axis coincides with the geometrical axis of the spindle a.

P is a heavy fly-wheel mounted on the spindle a and carrying at its circumference an iron armature A and a nose S, projecting inwardly and intercepting the U-shapedrod B. In the center of the fly-wheel P a sleeve 0, Fig. 3, is attached, to which latter is fastened one end of a powerful spring 1, the other end of which is held in a slot cut in a binding-post U, which is attached to the frame of the instrument. A second bindingpost U is attached to the fly-wheel and carries one end of a spiral spring f the other end of which is attached to the U shaped rod B and compels it to rest against the projecting nose S and thus follow the movements of 8 5 the fly-wheel P.

The binding-post U carries a small disk 10 with a projecting arm 20 with an eye bored at its free end, into which the spring f is hooked, and by a screw it the disk it can be fixed in different positions giving more or less tension to the spring f Opposite the armature A an electromagnet E is securely fastened to the frame of the instrument.

On the spindle a which carries the flywheel P, a clamp O is secured, (see Figs. 3, 5, and 6,) which carries a piece XV, provided with three noses n n 92- On the clamp O a spring f is fastened by a screw. The free 100 end of this spring f rests against the nose n of the piece \/V and is bent in a zigzag shape, so as to allow the piece WV two positions of restviz., the one drawn with full lines and the other drawn with dotted lines in Fig. 6. The piece W is so pivoted in the clamp O that it can freely turn to the right, but rests against a projecting portion 2' of the clamp in the position drawn in Fig. 6, so that it cannot turn any farther to the left. The nose it projects farther backward from the fly-wheel P than the noses at and n 0: and y are two pins fixed in the frame of the instrument, the one, or, being longer, so that it intercepts the nose n as it swings round the spindle a and the other, y, being shorter,

so that it allows the noses n and n to pass it freely, but intercepts the nose a J, J and J 3 are three metal blocks secured to the frame of the instrument (see Figs. 3, 5, and 6) and isolated therefrom. The block J carries a contactscrew S. The block J carries a spring f which carries a contactbutton 0, preferably made of pla tina and corresponding to the aforementioned contactscrew S. The spring f is so adjusted that in its position of rest the contact 0 remains closed and that its free end. carrying the contact-button 0 just intercepts the end of the nose or of the piece WV as the latter swings round the spindle a together with the flywheel P. The spring is further provided with a second contact-button 0 making contact with a spring f which is fixed to the block J but the relative adjustment of the springs f and f is made so as to leave the contact a open when the two said springs f and f" are in a position of rest.

H is a plug screwed into the frame of the instrument in such a position as to intercept the movement of the U-shaped rod B as the latter swings round the pins p and p together with the fly-wheel P. (See Figs. 2 and 4.)

The electric connections of the instrument are shown in Fig. 6.

w and 10 are two resistances, which are not shown in the other drawings,beca use they are made in the ordinary way. It will be readily seen that when the spring f closes the contact 0 the magnet E is short -circuit-ed, and when, on the other hand, the contact c is closed the magnet E will be excited and the coils m and m of the magnet E will in their turn be short-circuited.

WVhen the apparatus is at rest, the spring f is so adjusted that contact 0 is disconnected. This implies that contact is closed. In this position the electromagnet E or the coils m and m are short-circuited, since the current can pass through the wire connecting L with binding-post J, through spring f ,into spring f", into binding-post J and the wire connecting the latter with the resistance w and the binding-post and since the coils m and m constituting the magnetE are likewise placed between the conductor L and the resistance to. The electromagnet E however, is not short-circuited. It is true that the current can pass along the way indicated, but before reaching the binding-post to which the electromagnet E is connected, it has to pass through the resistance w, and if the resistance of the magnet E together with the resistance 10 is not disproportionately greater than the said resistance w a considerable or at any rate a sufficient portion of the current will pass through the coils of this magnet. The same holds good for E and 10 when the contact 0 is closed and in consequence the contact 0 is open.

10 is a resistance inserted in either of the two conductors L and L which form the working circuit the current of which is to be registered. Between the terminals of this resistance 1.0 the movable coil J is placed. This way of connecting the movable coil J, I con sider to be preferable in most cases, because the current flowing in L and L will, under ordinary circumstances, be too large to be conveniently carried through the movable coil, the wire of which will have to be made very thin for the sake of lightness, However, it will be understood that any connection will give the desired result which causes a current to How through the movable coil the strength of which is proportional to the working current which is to be registered.

The operation of the instrument is as follows: The spring f is so adjusted that the fly-wheel P, and in consequence the clasp O and the piece \V, when uninfiuenced by any other force, take such a position that the springf is lifted off from the contact 0. Care is taken to make the liy-wheel P perfectly symmetrical in every direction relatively to the spindle a so that if its position of restis adjusted by the spring f in one position of the whole instrument it will be the same for anyotherposition. Thisisimportantbecause it implies that no special care need be taken in hanging the instrument. As soon as the instrument is switched onto a source of electricity the electromagnet E will be excited and will attract the armature A, thereby imparting motion to the fly-wheel. The nose atwill consequently pass the spring f which will fall back upon contact a and thereby shortcircuit the magnet E The fly-wheel P once set in motion will continue to turn until the resistance of the spring f increases and gradually consumes its momentum, which, being stored in said spring, will reverse the motion of the fly-wheel. On its backward way the nose n passes the spring f without disturbing the contact 0. The tension of the spring f again comes into play, stopping and reversing the fly-wheel, and in the moment in which the nose n again passes the spring f the electromagnet E is again excited for a short time and gives an impulse to the armature A. Thus a continuous oscillating motion of the fly-wheel P is kept up, the whole device actually being in every way equivalent to an ordinary chronometer-balance.

In order to secure perfect regularity and constancy of the period of oscillation of the fiy-wheel, it is necessary to provide means for keeping the length of the oscillations as nearly constant as possible. For this purpose the device shown in Fig. 6 is provided. hen the oscillation of the fiy-wheel P becomes too long, the projecting arm a of the piece I is carried so far round the spindle a that it knocks against the pin 00. Consequently the nose if, by the action of its inclined surface, lifts the spring f and slips into its second position of rest. (Indicated in Fig. 6 by dotted lines.) In this position of the piece W the nose at passes the spring f freely, and the electro magnet E therefore remains short eircuited and no impulse is given to the fly-wheel P. On its way onward, however, the nose a now knocks against the pin y,and thereby the piece W is restored to its original position. If, therefore, the impulses imparted to the fly-wheel P by the electromagnet E at every oscillation are stronger than is necessary to keep up the desired rate of oscillation after a certain number of oscillations, always one impulse will be left out, and this number will adjust itself automatically in such a way that the mean length of the oscillations remains constant. However, though this device will tend to make the rate of oscillation constant, in order to make the instrument what is called directreading it is necessary to have the possibility of regulating the length of oscillation. lhis of course can be done in the way usual with ordinary clocks by lengthening or shortenin g the spring f, but I have found it desir able to provide a second and special means for obtaining this result.

It will be remarked that the U-shaped rod B is connected to the flywheel P merely by the spring f which presses it against the rest S. Now every time the fly-wheel P swings out in the sense opposite to that of the clockhand, as seen from above, (see Fig. 4,) and swings out farther than is desirable, the U- shaped rod B will knock against the plugscrew H and will be lifted off from the rest S, thereby extendingthe spring f until the tension of the latter becomes sut'ficient to reverse the motion of the flywheel. By adjusting the arm M to which the said spring f is attached, any suitable tension can be given to the spring f within practical limits, and by suitably adjusting the screw II the length of oscillation of the balance P can be altered within practical limits. As the balance P swings round, the U-shaped rod B is carried with it, but as the spring j", which is attached to the end of the rod B, is adjusted in such a way as to just pass freely round the edge of the disk R the registering device D will not be infl ueneed. However, it will be seen that except in those short intervals in which the spring f 5 is lifted off from the contact 0 and pressed against the contact 0 thereby short-circuiting the coils m and m these coils are excited, thereby causing a deflection of the movable coil J and consequently of the index Z is sufficient to slightly bend it when it strikes the latter while it is at rest. Thereby the end of the spring f will be brought into connection with the edge of the wheel R, which is provided with very fine teeth, so that the spring f will catch onto it and push it round as long as the motion of the balance P continues in that particular sense. As soon as the motion of the fly-wheel is reversed the spring f will be released and will in its turn allow the index Z to follow it and to assume its former position. Thus it will be seen that the registering apparatus D, which is coupled to the wheel R, is carried forward at every oscillation of the balance P, registering a part of the revolution of the wheel R which is equal to the deflection of the index Z. Consequently if the deflection of the index is proportional to the number of watts conveyed by the conductors between which the whole instrument is inserted the registering appara tus will at any time indicate the number of watt-hours that have been used.

If the instrument is intended to register coulombs instead of watts, the coils m and m are either excited by some independent and constant source of electricity or else the whole electromagnet E is replaced by a permanent magnet. It will be remarked that every time the nose n passes the spring f the contact 0 is closed, and thereby the coils m and m? of the measuring instrument are shortcircuited. I attach importance to this arrangement, as itis specially adapted to considerably in crease the exactness of the instrument.

If the coils of the measuring instrument remain inserted between the positive and the negative terminals every time the work which is being registered decreases, the instrument will tend to give faulty indications, because the iron contained in the coils m and m retains part of the magnetism once acquired. If, however, every time a registration is taken the coils are short-circuited and then excited afresh, this fault caused by hysteresis will be eliminated. A similar device may be provided to short-circuit the coil J before every registration, but this, for the sake of simplicity, is not represented and will not be generally found necessary, because the magnetic field caused by the coil J is naturally extremely weak.

I have found the form of measuring instrument described and shown specially adapted for use in current or watt meters made ac cording to my invention, but I would have it understood that any ordinary direct-reading instrument may be employed in which the deflections of the index are proportional to the number of amperes or watts measured.

Having now particularly described and as certained the nature of my said invention and the manner in which the same is to be performed, I declare that what I claim is- 1. A11 improved electricity-meter consisting of a suitable directreading electrical measuring instrument an oscillating balance and a registering-wheel all said parts being c011- centrioally pivoted, means for registering the revolutions of said wheel and means for coupling the said balance with the said wheel at every oscillation at the points indicated by the deflections of the needle of the measuring instrument.

2. An improved electricity-meter consisting of a suitable direct-reading electrical measurin g instrument, a wheel provided with means for registering its revolutions, and an oscillating balance provided with a flexible tongue fixed in the plane of said wheel and adjusted in such a way as to just clear its circumference, the index or needle of the said measuring instrument being provided with a similar tongue, which is adjusted in such a way as to intercept the oscillatory motion of the first-mentioned tongue, substantially as and for the purpose described.

3. An improved electricity-meter consisting of a suitable direct-reading electrical measuring instrument, a wheel provided with a finely-toothed edge, means for registering the revolutions of said wheel an oscillating balance, provided with means for propelling said wheel at every oscillation at a rate proportional to the deflections of the'needle of said measuring instrument and with an armature fixed at or near the circumference of said balance a fixed electromagnet and means to close and open the exciting-coils of said magnet at every oscillation of said balance substantially as and for the purpose described.

4. In an electricity-meter comprising an oscillating balance a direct-reading electrical measuring instrument a registering wheel and means for coupling the said balance with the said registeringvheel at every oscillation of the former and at those points of every oscillation that are indicated by the needle of said measuring instrument, means for interrupting the excitingcurrent of the said measuring instrument once during every oscillation of the said balance, substantially as and for the purpose set forth.

5. In electricity-m eters comprising a directreading electrical measuring instrument a registering-wheel, an oscillating balance and means for keeping up the oscillations of the same, a U shaped rod pivoted concentrically with the aforesaid parts, and coupled to said balance by means of a spring which presses it against a projecting nose fixed on said balance, said U -shaped rod being intercepted by a plug-screw fixed in the frame of the instrument and being provided with means for intercepting the index of said measuringinstrument and propelling the said registeringwheel, substantially as and for the purpose set forth.

6. In electricity-meters comprisingadirectreading electrical measuring instrument, a

'registering-wheel an oscillating balance,

means for coupling said balance with said registering-wheel at those points of every oscillation of the same which are indicated by the needle of said measuring instrument and a fixed electromagnet acting upon an armature fixed on or near the circumference of said balance, means for exciting said electromagnet for a short time during every oscillation and means for leaving out one of the said excitations every time the oscillations of said balance-have increased beyond a certain prefixed rate, substantially as and for the purpose set forth.

In testimony whereof I have affixed my signature in presence of two witnesses.

AUGUST RAPS.

Vitnesses:

JOHN B. JACKSON, MAX TRAGAER. 

